Differential fluid pressure line control



G. E. MILLER DIFFERENTIAL 'FLUID PRESSURE LINE CONTROL Nov. 7, 1939 Filed m 15, 1938 2 Sheets-Sheet 1 3 PW c/wbo o Geo/ye MW/er Nov. 7, 1939.

DIFFERENTIAL FLUID PREHSSURE LINE CONTROL Filed July 13, 1938 G. E. MlLl JR 2.179.267

2 Sheets-Sheet 2 F1 IE: 5.

- Q 70 .45 74 L-7/ v 77 J 76, f k I J/ 50 14 M I I i f F IE: 4

gwua/wtc o open to the vacuum source. In other words, when the control handle 41 is moved in one direction from neutral position, the clutch 6 is engaged, and when moved in another direction from such position, the clutch l is engaged.

The novel feature in the present invention resides particularly in the brake control through the medium of the relay valve 42. This valve, in its present embodiment, comprises a housing 50 divided by a partition 5| into two spaced compartments'52 and 53 (Fig. 3). The compartment 53 is divided by spaced diaphragms 54 and 55 into three chamber 56, 51 and 58. The chamber 56 is in communication with the vacuum line 45 through tubes 59 and- 45, which tubes are in controllable communication through a three-way valve 60. The chamber 57 is in communication with the vacuum line 46 to the clutch'member through a branch tube 46'. The vacuum connection with the chamber 58, which is for a sepa; rate manual control, will be hereinafter described.

The compartment 52 has a nipple 65 projecting therein from its outer end toward the compartment 53, its outer end being connected to. the tube 36 leading to the brake cylinder 35, while its inner end is constantly open to the compartment 52. A diaphragm 66 is disposed across the compartment 52 in opposition to the nipple 65, which latter acts as a stop for limiting the movement in one direction of the diaphragm. In the present instance, the nipple 65 is shown as being of tubular form with its lower end notched to provide projections serving as a stop for the diaphragm 66 and also toprovide passages opening communication between the compartment 52 and interior of the nipple.

A stem 61 is fixedly connected to and projects from the diaphragm 66 through a suitable gland in the partition 5| and connects to both diaphragms 54 and 55 in a manner to cause the diaphragm 66 to move outward when either diaphragm 54, 55, has such a. movement imparted thereto by vacuum action. A coiled expansion spring 68 is disposed between the bottom of the partition 5| and the diaphragm 66 and serves to normally hold the diaphragm 66 in stop enagement with the nipple 65.

Leakage in any suitable manner may be provided between the chamber 52 and the portion of such chamber below the diaphragm 66 in which the spring 68'is disposed, so as to permit free inward and outward movements of the diaphragm 66.

The compartment 52, except for the valve 18 therein when closed, is in communication with the vacuum source (tank 48) through tubes ll, 12, I3 and 43. The compartment 52 also has communication with the atmosphere through a port opening 14 and housing 15, the port 14, in

the present instance, being at the opposite side of said compartment to the port 76 with which the tube H is connected. The port I4 is closed at its outer side by. an outwardly opening valve 11, while the valve 18, which closes the port 16,

is inwardly opening. These valves, in the present instance, have stems projecting inwardly therefrom in parallel relation through registering bearing openings in the walls of the nipple 65. The diaphragm 66 has suitable link connection with such valve stems so that an outward movement of said diaphragm away from the nipple 65 will cause a positive opening of the valve 18 and closing of the valve 11, and vice versa.

For the purpose of this connection, the diaphragm 66, in the present instance, is provided with a -U-shaped yoke 88 projecting up into the nipple 65 in straddling relation to said valve stems, which are disposed one without the other, and has'one of its legs connected by a rocker 8| to the stems of the valves 10 and 17. The rocker 8| is pivoted at its inner end to the yoke 88 and projects outward therefrom through a side opening in the nipple. 65 in substantially parallel relation to the associated valve stems and is pivoted to said stems at 82 and 83, respectively. Upon a lowering of the yoke 88, the rocker 8| first fulcrums about the point 82 due to the seating thrust of the valve 16, thus causing the valve 1'! to be drawn inward to its seat. When the valvejll reaches its seat, the pivot 83 then stands stationary and the continued outward movement of the yoke causes the rocker to fulcrum about such point and to draw the valve 10 from its seat. It is thus apparent that upon an outward movement of the yoke 80, the air valve 11 is closed before the vacuum valve I8 is opened.

It is apparent from the above description that the line connection between the brake vacuum cylinder 35 and the vacuum source 48 is normally closed by the valve 10, so that the brake 30 is normally engaged by the action of the spring 32. Also, upon a movement of the control lever 41 to permit vacuum actuation of either clutch 6 or E, vacuum action takes place in one or the 42, so as to draw the associated diaphragms outward and impart an opening movement to the valve i0 and a closing movement to the air valve Tl. This places the brake cylinder 35 in communication with the vacuum source so as to efiect a release of the brake at the same time one or the other of the clutches 6, l, is engaged by vacuum action.

The chamber 58 of the relay valve 42 is connected by a tube 85 through a manual control valve 86 with the. vacuum source 48, such connection,.in the present instance, being through the tubes 43, 13 and 12. The valve 86 is normally closed. When it is desired to eflect manual instead of automatic control of the relay valve 42, the three-way valve 60 between the tubes 45' and 59 is turned to the right to close the communication between such tubes and to open the communication between the tubes 59 and 12. 'This opens the vacuum chamber 56 in the relay valve 52 to vacuum action which is constant, so long as the three-way valve 68 is in such position. Such constant vacuum action on the diaphragm 54 draws the stem 61 and its diaphragm 66 downward, causing a movement of the rocker 8| to effect a closing;of the air valve TI and an opening of the vacuum valve 10, which latter 0 ens the brake cylinder 35 to the vacuum action an maintains the brake in released position. Either clutch 6 and I may now be engaged by v cuum action through a manipulation of .the cbntrol valve handle 41 without imparting any action to tive turning of the platform in one direction or the other. If it is desired to engage the brake at any time during an operation of the machine, the operator moves the manual control handle of the by the valve 10, andthe'btake cylinder is open to the atmosphere through the port valve '86 to open the communication or the vacuum source with the relay valve chamber 58 through the tube 85. When this is done, the vacuumwithin the chamber 58 acts on the diaphragm 55 and draws it upward to effect a closing of the shut-off valve III and an opening of the air valve 11, thus releasing the vacuum action in the brake cylinder and permitting the brake to be applied by the actionof its spring. The diaphragm 55 is larger than the diaphragm 54 so that the vacuum action within the-chamber 58 onthe diaphragm 55 is greater than the corresponding action or the diaphragm 54 within the chamber 55. The operation of the apparatus is as follows: When the three-way valve 99 is in the position indicated in Fig. 3, which closes the communication between the tubes 59 and "and opens the communication between the tubes 59 and the apparatus is in condition for automatic operation, wherein the brake 30 is'normally applied, and is automatically released by vacuum action when the automatic control valve 44 is manipulated to permit a vacuum actuation of eitherclutch B, I, to fiectran application thereofLIn -this automaticcontrol of the brake, the vacuum line 12, 36, to the brake cylinder is normally closed I4. When either cylinder l0, II, is open to the vacuum source through the valve 44 to effect an application of the respective clutch B, I, one or the other ofthe chambers 56, 51, of the relay valve 52 is also open to the vacuumsource through the respective tubes -46, 59, thus actuating one or the other of the diaphragms 54 5 5,to move the stem 61 and its diaphragm 66 outward away from the nipple 65, thereby eifecting a rockingoi' the rocker 8| and a consequent closing of the air valve 11 and opening of the vacuum valve 19. This places,

the brake cylinder 35 in communication withthe vacuum sourceso that the release of the brake is effected. When it is desired it 'plac'egthe brake 39 under manual control 'inst'ea three-way valve 89 is turned munication between the tub to open'the communication J V 59 and 12. This places the chambe 59in constar-1t communication with a vacuum source through said tubes iii-and 12,-and causeothe'istem 61 and its diaphragms to be held at theilimit of i automatic, the

lose the comtheir outward movements, in which 'positlonthe shut-off valve [0 is held open and the air-relief valvel'l closed. This causes the brake to-nor- "mally stand in released position under vacuum action and' against thetension of the brake spring. Whenever it isdosired to apply the brake,

the operator-manipulates the valve 85 to open the tube 85 and'chamber 58 to the vacuum source, so that the vacuum action within said chamber acting on the diaphragm will move the stem 61 and. its diaphragms in an upward or inward direction to-eflect a closing of the shut-offyalve l0 and an opening 01! the relief valve 11, thus releasing the vacuum action in the brake cylinder. A control of this character, whereby the releasing action 01' the brake may be automatic, upon the application of either clutch, or where the control of the brake'may be manual so that the brake may be applied at the will of the ope'rator at any period in an operation of theapparatus, is important in connection with the operation of certain types of mechanism with which the control may be associated, as is apparent to persons skilled in the art.

and 59-, and

I wish it understood that my invention is not limited to any specific construction, arrangement or form or the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent, is: e

1. In combination, a driven member, a clutch means and a brake means associated therewith, one having an applying and the other a releasing action imparted thereto .by vacuum action, a vacuum source,'means establishing communication between said source and each of said clutch and brake means and including a control .valve and an automatic valve, said automatic valve having a vacuum shut-oil? valve and a relief valve in said brake communication and also having vacuum actuatedfmeans to open said shut-oil? valve and close said relief valve, said control valve being operable to permit vacuum actuation of said last means and vacuum actuation of said clutch.

2. In combination, a vacuum actuated member,

3. In combination, a vacuum actuated member, a vacuum source, means establishing communica-' tion between said source and member and having an automatic valve, said automatic valve including a shut-off valve for said communication and an air inlet valve for said communication between said member and shut-off valve, said automatic valve also including spaced diaphragms, each having separate exposure at the same side thereof to the 'vacuum source and both connected to said shut-off and. air valves to open the former and close the latter when vacuum actuated, said means also including a control operable to selec tively expose. the diaphragms to vacuum action.

4; In combination, a driven member, a clutch means and a brake means associated therewith and each having a predetermined action imparted thereto by vacuum action, a vacuum source, a 2 connection between said source and clutch means,

a connection between said source and brake means, a normally closed valve in said last conneetion, vacuum actuated means operable to p the valve, said first connection having com municationwith said valve, and a control in said first connection for opening and closing communication between said source and clutch cans and said valve to eflect a vacuum actuated a tion 01 the clutch means and an opening of said v ,ve.

5. In combination; a driven member, a clutch and brake associated therewith, means for effecting a vacuum actuated engagement of the clutch and release of the brake, said means including vacuum source, a communicating line between said source and clutch, a second commun cating line between said source and brake, a manual control valve in said first line, and a relay valve 6. In a control of the. class described, a driven member, a clutch and a brake associated therewith, the clutch being normally released and the brake normally engaged, a vacuum source having releasing connection with the brake, a shut-off valve normally closing said connection, said source also having a valve controlled connection both with the clutch to eflect application thereof and with said valve to open same.

7. In a control of the class described, a driven member, a clutch and a brake associated therewith, the clutch being normally released and the brake normally engaged, a vacuum source having releasing connection with the brake, an automatic relay valve normally closing said connection and havinga vacuum actuated diaphragm for opening the valve when subjected to vacuum action, said source also having connection with said clutch and with the diaphragm of said valve, and means for controlling said last connection to open or close connection between the source and both said clutch and said diaphragm.

8. In a control of the class described, a driven member, a clutch and a brake associated therewith, the clutch being normally released and the brake normally engaged, a vacuum source having releasing connection with the brake, an automatic relay valve normally closing said connection, said source also having a valve controlled connection with the clutch to effect application thereof and with said valve to open same, means for disconnecting said last connection from said diaphragm, and manually controlled means to efiect vacuum actuated opening of said valve independently of said valve controlled connection.

9. In a control of the class described, a driven member, a drive means therefor including separate direct and reverse drive clutches, holding means for said member, a vacuum source having connection with said brake to impart predetermined action thereto, an automatic relay valve in said connection ha-ving separate diaphragms connected to the valve and each operable by vacuum action to open the valve, said source also having selective valve controlled connection with each of said clutches to apply a predetermined action thereto and each connected to a separate one of said diaphragms to effect an opening of the valve when either clutch is in operating con nection with said source.

10. In a control of the class described, a driven -member, a drive means therefor including separate direct and reverse drive clutches, holding means for said member, a vacuum source having connection with said holding means to impart predetermined action thereto,an automatic relay valve in said connection having separate diaphragms connected to the valve and each operable .by vacuum action to open the valve, said source also having selective valve controlled connection with each of said clutches-to apply a predetermined action thereto and each connected to a separate one of said diaphragms to efiect an opening of the automatic valve when either clutch is in operating connection with said source, means for disconnecting one of said clutch connections from its diaphragm and to open said source to such diaphragm to normallyhold said automatic valve open, and means connecting said source and automatic valve and manualy controlled to effect an opening of the automatic valve.

11. In combination, a driven member, drive means therefor in separate clutch connection therewith to drive it in one direction orthe other, -aholding means for said member, a vacuum source having separate operating connections with said holding means and each clutch to release the holding means and apply the clutches -by vacuum action, a normally closed automatic control for the holding means connection and in operating connection with each of said clutch connections to cause said control to open when the connection to either clutch is open, and means operable to open or close either clutch connection.

12. In combination, a driven member, drive means therefor in separate clutch connection therewith to drive it in one direction or the other, aiholding means for said member, a vacuum source having separate operating connections with said holding means and each clutch to release the holding means and apply the clutches by vacuum action, an automatic valve in said holding means connection, means connected to and normally operating to close said valve, said last means having communication with each of said clutch connections and operable by vacuumv action therein to eifect an opening of said valve when either clutch connection is opened to the vacuum source, and manual control means for said clutch connections.

13. In combination, a driven member, drive means in clutch connection therewith, a holding means for said member, a vacuum source having separate operating connectionsrwith said holding means and said clutch to release the holding means and apply the clutch by vacuum action an automatic valve normally closing said holding means connection, an operating means for said valve normally holding it in closed position and vacuum actuated to open the valve, a manual control in said clutch connection to open or close said connection with the source, and a connection between said operating means and clutch connection to efiect vacuum actuation of the operating means to open said valve when the control in said clutch connection is open.

' 14. In combination, a driven member, drive means in clutch connection therewith, a holding means for said member, a vacuum source having separate operating connections with said holding means and said clutch to release, the holding means and apply the clutch by vacuum action, an automatic valve norm'ally closing said holding means "connection, an operating means for said valve normally holding it in closed position and vacuum actuated to open the valve, a manual control in said clutch connection to open or close said connection with the source, and a connection between said operating means and clutch connection to eifect' vacuum actuation of the operating means to open said valve when the control in said clutch connection is open, means operable to close the connection between said operating means and clutch connection and to open'said operating connection to said holding means connection at the source side of said valve to cause actuation of the operating means to normally hold said valve open, and a separate manually controlled connection between said operating means and source adapted when open to permit vacuum actuation of the operating means to close said valve.

15. In combination, a vacuum actuated memher, a vacuum source, a connection between said member and source, a valve for closing said connection, an operating means for said valve including a plurality of diaphragms having connection with the valve, a second and third connection between said diaphragms and' source,

hill

each having a control therein, whereby when one connection is opened and the other closed the valve is held opened by vacuum action on the associateddiaphragm, and vice versa, means lor closing one of said second and third connec-' tions to-said source and opening it to said flrst connection to cause the valve to be normally held open by vacuum action from said first connection when the other of said second and third connections is'closed to the vacuum source.

16. In combination, a line having fluid pressure therein difiering from atmospheric pressure, a

shut-oil valve and a relief valve in said line, means connected to each valve and operable to close one and open the other and vice versa, and separate controlled means, one of which is operable to actuate said first means to close the shut-oil valve and open therelief valve and the other being operable to actuate said first means to impart opposite movements to said valves from those imparted by the companion means.

it. In combination, a line having fluid pressure therein differing from atmospheric pressure,

a diherential fluid pressure source in connection wil with said line, a shut-oil valve in said line, means forming a plurality of chambers with movable diaphragms therein, connection between said diaphragms and valve'operable-by predetermined movements of the diaphragms to open or close the valve, separate controlled connections between said source and diiierent of said chambers to cause the diflerentialfluid pressure to act through one connection on one diaphragm to close the valve and through another connection on another diaphragm to open the valve, and a relief valve in said line connected to the shut-oil valve and automatically movable to open position when the shut-oil valve is closed, and vice versa. 18. In combination, a line having fluid pressure therein differing from atmospheric pressure, a

tion between said source and one of said chambers adapted whenopen topermit diflerential fluid pressure to act on the diaphragm to close the valve;

19. In combination, a line having fluid pressure therein differing from atmospheric pressure, a' differential fluid pressure source in connection with said line, a shut-oil valve in said line, means connected to and acting on said valve to normally hold it in closed position,and operable to pneumatically impartopening and closing movements of said valve, said last means including at least three separate connections between said source and first means, a common control in two of said connections operable to open either connection to permit difierential fluid pressure actuated opening movements of said valve, means operable to cause at least one of said connections to be normally open to said source to maintain the valve in open position, a third one of said connections permitting differential fluid pressure from said source to act on said flrst means to close said valve, and a manual control in said third connection.

20. In combination, a normally released clutch and a normally engaged brake, means pneumatically operable to engage said clutch, means pneumatically operable to release said brake, a valve associated with said last means and movable to closed position to render saidlast means inoperative, means acting to normally retain said valve closed, means pneumatically operable to open said valve when said first meansjoperates to engage the clutch, means for rendering said last means non-sensitive to a clutch engaging action of said first means and adapted to cause it to act to normally hold the valve open, and manually controlled means pneumatically operable to close the valve against said pneumatic opening pressure means. 7

V 21. In combination, a driven member, a drive therefor including two separate normally released clutches for. driving it in one direction or the other and a normally engaged brake, means pneumatically operable to selectively engage either clutch, means pneumatically operable to release said brake, a valve associated with said last means and movable to closed position to render said last means inoperative, means acting to normally retain said valve closed, means pneumatically operable to open said valve when said first means operates to engage either clutch, means for rendering said last means non-sensitive to clutch engaging action of said first means and adapted, to cause it to act to normally hold the valve open, and manually controlled means pn'eu matically operable to close the valve against said pneumatic opening pressure means.

, GEORGE E. MILLER; 

